$A$ person in front of a mountain is beating a drum at the rate of $40$ per minute and hears no distinct echo. If the person moves $90 \, m$ closer to the mountain,he has to beat the drum at $60$ per minute to not hear any distinct echo. The speed of sound is .............. $ms^{-1}$.

Write the equation for the speed of a sound wave in air.

The ratio of the speed of sound in helium gas to that in nitrogen gas at the same temperature is $\left(\gamma_{He}=\frac{5}{3}, \gamma_{N_2}=\frac{7}{5}, M_{He}=4, M_{N_2}=28\right)$

The enclosed air inside a closed box of rigid walls has pressure $P_1$. The density of air inside this box is constant. On heating the gas, the pressure of the enclosed air is increased from $P_1$ to $P_2$. Now it is observed that the sound travels $1.4$ times faster than at pressure $P_1$. The ratio $P_2/P_1$ is:

What is the ratio of the velocity of sound in hydrogen $\left(\gamma=\frac{7}{5}\right)$ to that in helium $\left(\gamma=\frac{5}{3}\right)$ at the same temperature? (Molecular weight of hydrogen and helium is $2$ and $4$ respectively)

What will be the shape of the graph of the speed of sound in air versus pressure at a constant temperature?